Safety needle assembly

ABSTRACT

The present invention is directed to a safety needle assembly having the high safety and high operability, comprising: a hub; a cannula; a collar; a protector; and a sheath. The sheath includes an opening of housing the cannula; a cannula fixing part of locking the cannula housed in the opening; an attachment part of rotatably supporting the sheath attached to the hub or the collar; and a protrusive stopper which a user pushes by a finger to pivot the sheath thereby to house the cannula in the opening of the sheath. Herein, the stopper is arranged at a vicinity of a central portion of the sheath in a longitudinal direction at the opposite side of the aperture of the opening, or arranged at a portion closer to a distal end side than the central portion of the sheath.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a needle assembly having a safety mechanism (that is, comprised of a needle and attachment parts).

2. Description of the Related Art

Conventionally, different types of needles such as needles for a hypodermic syringe and a catheter have been applied to a medical tool. Here, a user (such as a health care worker) has to safely handle those needles. Otherwise, if a user erroneously sticks such a needle used for a patient or the like into the user's own body (finger or the like), the user may be infected with a disease.

Herein, there may be a method for preventing such a sting accident from happening, for example, including a means of covering a used needle with a cylindrical cap. However, even in this method, a user may erroneously stick a needle into one of user's fingers holding the cap. Therefore, this method cannot be perfectly safe for preventing a sting accident.

Regarding other methods, for example, Patent Documents 1 and 2 disclose a technique for preventing a sting accident by using a needle assembly comprised of a sheath (or shield) for covering a needle. According to that technique, a user can utilize the needle assembly in the steps of: using a needle for a medical treatment; pivoting a sheath by finger(s) so as to cover the used needle with the sheath; and fixing the state that the used needle is covered by the sheath.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: JP 2000-140109

Patent Document 2: JP 2005-525198

However, it should be noted that the technique disclosed in Patent Document 1 needs large force for using the needle assembly, since there is only a short distance between a fulcrum of the pivoting sheath and a position on the sheath which a user pushes by a finger. This results in the poor operability of the needle assembly.

Further, according to a technique disclosed in Patent Document 2, no stopper which a user pushes by a finger to pivot a sheath is provided with the needle assembly. This also results in the poor operability of the needle assembly.

Accordingly, from the viewpoint of the above mentioned drawbacks, the present invention has been developed so as to provide a safety needle assembly having the high safety and operability.

MEANS FOR SOLVING THE PROBLEMS

The present invention is directed to a safety needle assembly including a sheath having the following features. That is, the sheath comprises: a hub including a proximal end connecting with a syringe, and a distal end; a cannula having a proximal end connecting with the distal end of the hub, a lumen extending in a longitudinal direction of the cannula, and a distal end; a collar attached to the hub and having a sheath attachment part; a protector covering the distal end of the cannula by being attached to the hub or the collar, and being detachable to expose the distal end of the cannula; an opening partially extending along at least a longitudinal direction of the sheath so as to house the cannula.

The sheath further comprises: a cannula fixing part of locking the cannula housed in the opening; an attachment part rotatably supporting the sheath in a direction of housing the cannula when the protector is detached to expose the distal end of the cannula, the attachment part being attached to the sheath attachment part of the collar; and a protrusive stopper arranged at a vicinity of a central portion of the sheath in a longitudinal direction in which the central portion is located at an opposite side of an aperture of the opening, or arranged at a position closer to the distal end of the sheath than the central portion. Herein, a user's finger pushes the stopper on the sheath so as to house the cannula in the opening.

The above mentioned mechanism allows the safety needle assembly to realize the high safety. Further, the sheath provided with the protrusive stopper arranged at a vicinity of a central portion of the sheath in a longitudinal direction, or arranged at a position closer to the distal end of the sheath than the central portion also allows the safety needle assembly to realize the high operability.

More specifically, the stopper located at the position as described above enables the user to push the stopper on the sheath by a finger at a far position from the fulcrum, allowing a large moment to be generated. This large moment enables the sheath to be pivoted by relatively small force.

Further, the present invention is also directed to a safety needle assembly including a sheath having the following features. That is, the sheath comprises: a hub including a proximal end connecting with a syringe and a distal end; a cannula having a proximal end connecting with the distal end of the hub, a lumen extending in a longitudinal direction, and a distal end; a collar attached to the hub and having a sheath attachment part and a pair of sheath fixing protrusions; a protector covering the distal end of the cannula by being attached to the hub or the collar, and being detachable to expose the distal end of the cannula; and an opening partially extending along at least a longitudinal direction of the sheath so as to house the cannula.

The sheath further comprises: a cannula fixing part comprised of grooves respectively fitting with the pair of sheath fixing protrusions when the cannula is housed in the opening, and a pair of wing walls each of which has a slope arranged inside the wall in a direction from the groove to the proximal end of the sheath; and an attachment part rotatably supporting the sheath in a direction of housing the cannula when the protector is detached to expose the distal end of the cannula, the attachment part being attached to the sheath attachment part of the collar.

The above mentioned mechanism allows the safety needle assembly to realize the high safety. Further, the sheath provided with the pair of wing walls including the grooves and slopes allows the safety needle assembly to realize the high operability. More specifically, the wing wall protruding from the sheath body has flexibility to be easily bended outside. Further, the slopes allow the sheath fixing protrusions located on the collar to be more easily introduced into the grooves. Moreover, the grooves facilitate the sheath fixing protrusions of the collar to be fixed with the sheath.

Accordingly, this construction enables the sheath fixing protrusions located on the collar to be fitted and fixed to the gloves in the wing walls of the sheath, by relatively small force when a user pushes the sheath by a finger.

Further, in the present invention, preferably the sheath comprises a circular recess, and a slope having a plurality of protrusions and recesses with large frictional resistance arranged between the circular recess and the stopper. Herein, the circular recess and the slope are used as a finger guiding region to which a user's finger of operating the sheath contacts, and arranged at a position closer to a proximal end side than the stopper arranged at the opposite side of the aperture of the opening.

The above mentioned construction enables the user to push the sheath at either of the positions at: the circular recess to which a user's finger easily fits, or the slope having a plurality of protrusions and recesses with large friction resistance. Accordingly, this enables the safety needle assembly to realize the high operability.

Further, in the present invention, preferably the sheath comprises a locking tab inside the opening as a cannula fixing part, the locking tab protruding from the side wall of the opening to the inside thereof. Herein, the locking tab passes the cannula introduced in the opening, and then fixes the cannula.

This construction enables the cannula housed inside the opening of the sheath to be fixed by a locking tab which is easily molded. Hereby, the cannula fixing part can be produced at low cost.

Further, in the present invention, an attachment part of the sheath is comprised of cylindrical pins. Herein, the sheath attachment part of the collar is preferably comprised of protruded ears, including a pair of through halls of respectively housing the cylindrical pins, and inside chamfers of receiving the respective cylindrical pins.

According to the above mentioned construction, the ears of the collar respectively have the chamfers inside the ears. Hereby, when the sheath is to be attached to the collar, relatively small force is only needed for attaching the sheath to the collar via the chamfers.

Further, in the present invention, preferably the pair of sheath fixing protrusions located on the collar respectively has a substantially triangle shape and are arranged at the opposite position of the sheath attachment part. Further, preferably the pair of sheath fixing protrusions has grooves respectively fitting with a pair of wing walls of the cannula fixing part.

The above mentioned construction enables the pair of sheath fixing protrusions of the collar to be realized respectively in a simple structure like a substantially triangle shape having a groove.

EFFECT OF THE INVENTION

According to the present invention, a safety needle assembly having both high safety and operability is provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view showing the components of a safety needle assembly in a present embodiment.

FIG. 2 is a perspective view of a hub which is a component of a safety needle assembly.

FIG. 3A is a perspective view of a collar which is a component of the safety needle assembly.

FIG. 3B is a perspective view of the collar, as seen from a back side of the collar in FIG. 3A.

FIG. 4 is a perspective view of a protector which is a component of the safety needle assembly.

FIG. 5A is a perspective view of a sheath which is a component of the safety needle assembly.

FIG. 5B is a perspective view of the sheath as seen from a bottom side of the sheath in FIG. 5A.

FIG. 6 is a perspective view of the safety needle assembly representing a state that all the components are assembled.

FIG. 7 is a perspective view of the safety needle assembly representing a state ready to be used. This state is prepared by removing a protector from the safety needle assembly in FIG. 6, and exposing a cannula via pivoting the sheath.

FIG. 8 is a perspective view of the safety needle assembly representing a state just before the cannula is to be housed in the sheath. The state is prepared by pivoting the sheath in the state of the safety needle assembly shown in FIG. 7, after the safety needle assembly has been used.

FIG. 9A is a perspective view of the safety needle assembly representing a state that the cannula is housed in the sheath. This state is prepared by a user to push a sheath via a finger, the sheath being in the state of the safety needle assembly shown in FIG. 8.

FIG. 9B is a perspective view of the safety needle assembly as seen from a bottom side of the safety needle assembly in FIG. 9A.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments for carrying out the present invention will be explained in detail referring to the attached drawings (or appropriately referring to the following descriptions besides the drawings).

Here, a safety needle assembly in the present embodiment is used via connected with a liquid transfer apparatus such as a syringe (hereinafter, simply called “syringe”). Here, the safety needle assembly is packaged by blister packaging or the like which is formed by extending a plastic sheet material. In this case, after treating such a packaged product, a user connects the safety needle assembly with a syringe. Alternatively, in the state being connected with a syringe, the safety needle assembly may be packaged as a product.

First, referring to FIG. 1, the whole construction of the safety needle assembly in the present embodiment will be explained. Note when each component of the assembly is explained, a “direction” described therein is defined by the respective directions in FIG. 1, showing “Up” and “Down” , “Front” (or distal end side) and “Back” (or proximal end side), and “Left” and “Right” . In other FIGS, the directions are similarly described to those in FIG. 1. Further, it should be noted that the “proximal end” and the “distal end” may include a peripheral portion of the “end” portion instead of only the “end” portion.

The safety needle assembly 100 includes a hub 1, a cannula 2, a collar 3, a protector 4 and a sheath 5. Note an assembly having no protector 4 is also called a “safety needle assembly 100”, as described hereinafter.

The cannula 2 is connected with the hub 1 in a general method, for example, using an epoxy resin. The cannula 2 includes a proximal end 21 connected with a distal end of the hub 1 and a distal end 22 having a blade surface 20. Note it is preferable to respectively mold the hub 1, the collar 3, the protector 4 and the sheath 5 as one-piece parts. However, the present embodiment is not limited to the above mentioned method, and a variety of methods can be applied.

The collar 3 is to be fitted with the hub 1 at a predetermined position. Further, the protector 4 is guided by the hub 1 to be fitted with the collar 3 and/or the hub 1, thereby to cover the cannula 2 at the fitting. Moreover, the sheath 5 is to be fitted with the collar 3 so that the sheath 5 can pivot on the collar 3. The detailed explanations will be described hereinafter.

As shown in FIG. 2, the hub 1 includes a distal end 10 and a proximal end 11 connected with a syringe (not shown in FIG. 2). Here, a through hole 12 extends along the entire length of the hub 1 in a longitudinal direction (or front-back direction). The through hole 12 has apertures at both distal end 10 and proximal end 11 thereof.

A distal end 21 of the cannula 2 in FIG. 1 is fitted and fixed with the inside of the through hole 12 at the distal end 10 of the hub 1 by using an epoxy resin. Accordingly, a lumen extending along the entire length of the cannula 2 is communicated with the through hole 12 inside the hub 1.

The distal end 10 of the hub 1 comprises a plurality of ribs 13 in a shape resembling a series of steps, with extending in a longitudinal direction. The ribs 13 facilitate the collar 3 to be fitted with the hub 1 in a coaxial manner (or having central axis “c” be coaxial).

A surface of the hub 1 includes a plurality of protrusions 14 projecting from a circumferential outside surface of the hub 1 to an outer side thereof in a radial direction.

Further, a recessed ring region 15 is located at a distal side of the protrusions 14. Accordingly, stage parts 16 and 17 neighboring the recessed ring region 15 have larger external diameters than the recessed ring region 15.

The proximal end 11 of the hub 1 has a flange 18 projecting to an outer side of the hub 1 in a radial direction. The flange 18 is engaged with, for example, a distal end of a syringe body (not shown). The engagement allows the hub 1 to be connected with the syringe body (not shown). This connection step may be performed by a known method, for example, by engaging the flange 18 with a screw (or female screw) located at a distal end of the syringe body (not shown).

As shown in FIGS. 3A and 3B, the collar 3 has an outline in a circular shape, having a proximal end 38 and a distal end 34. The collar 3 further includes a through hole 39 for the attachment to the hub 1. Here, an inside surface of the collar 3 has a plurality of protrusions 301 projecting to the internal side. Those protrusions 301 projecting to the internal side are engaged with the protrusions 14 of the hub 1. This engagement enables the collar 3 to be unratatably fixed onto the hub 1.

Further, the collar 3 includes a ring-shaped ridge 302 on an inner surface thereof. The ring-shaped ridge 302 is spread over the whole circumference at the inner peripheral side of the through hole 39. Hereby, when the collar 3 is attached to the hub 1, the ring-shaped ridge 302 is seated onto the recessed ring region 15 of the hub 1. Therefore, the ring-shaped ridge 302 has a smaller internal diameter than the external diameters of the two stages 16 and 17 directly neighboring to the recessed ring region 15 of the hub 1. In contrast, the ring-shaped ridge 302 has a substantially equal internal diameter to the external diameter of the recessed ring region 15 of the hub 1. Note the ring-shaped ridge 302 projecting to the internal side in the radial diameter is shown as a consecutive ring-shaped ridge. However, the ring-shaped ridge 302 may be formed, as comprised of a plurality of separated segments, each of which extends along a part of the inner circumference of the collar 3.

The collar 3 has a pair of ears 31 (or sheath attachment part) projecting to the external side in the radial direction. The upper half of the ear 31 has a shape formed by halving a substantially cylindrical shape lying on the side. The ear 31 includes an ear hole 33 with a cylindrical shape to which a pin 540 of the sheath 5 (as described hereinafter) is housed, and a chamfer 32. The chamfer 32 is arranged at an upper portion at the internal side of the ear 31, as shown in FIGS. 3A and 3B. The pin 540 of the sheath 5 passes along the chamfer 32, thereby to be housed in the ear hole 33.

Namely, a pair of ears 31 enables the sheath 5 to be rotatably attached to the collar 3. More specifically, the chamfers 32 facilitate a pair of pins 540 of the sheath 5 to be respectively attached to the pair of ears 31 of the collar 3. Further, when the pair of pins 540 is attached to the pair of ears 31, the pair of ears 31 slightly bends toward the external direction so that the ears 31 are estranged each other. Moreover, a thickness of the ear 31 may be appropriately determined by considering the strength for resistance to damage, and the flexibility for easier attachment of the sheath 5.

The collar 3 includes a ring-shaped ridge 36 projecting to the external side in the radial direction. The ring-shaped ridge 36 is a component for seating the protector 4.

The collar 3 further includes a pair of sheath fixing protrusions 35. The sheath fixing protrusion 35 has a substantially triangle shape, and is arranged at the opposite side of the ear 31. The sheath fixing protrusion 35 further includes a groove 37 which is to be engaged with a wing wall 53 (or cannula fixing part) of the sheath 5.

As shown in FIG. 4, the protector 4 is formed as a hollow member with an elongated cylindrical shape, including a distal end 40 and a proximal end 41. Preferably, the protector 4 is opened at the proximal end 41 and closed at the distal end 41. A plurality of ribs 42 are arranged in a longitudinal direction at a middle portion of the external surface of the protector 4, so that a user can easily hold the protector 4.

The protector 4 is arranged at the position to cover the cannula 2. This arrangement allows the protector 4 to cover up the distal end of the cannula 2. At that time, the protector 4 is fixed onto the collar 3 and/or the hub 1. Further, the protector 4 can be detachably pivoted so as to expose the distal end 22 of the cannula 2. Note a seating face (not shown) for the collar 3 may be arranged inside the protector 4 at the proximal end 41 thereof.

As shown in FIGS. 5A and 5B, the sheath 5 includes a proximal end 501 and a distal end 521, and is formed as an elongated member in the whole body. The sheath 5 includes an opening 58 extending along at least a portion of the longitudinal extent of the sheath 5. The opening 58 is an internal space of the sheath 5. In the present embodiment, the opening 58 of the sheath 5 extends along the entire length in the longitudinal direction. The proximal end 501 is opened in the longitudinal direction of the sheath 5, while the distal end 521 is closed in the longitudinal direction of the sheath 5.

Further, the sheath 5 includes finger guiding parts 50, 51 and a distal part 52, which are composed of a pair of side walls and a back wall. A circular recess 500 is arranged at the back wall of the finger guiding part 50. The circular recess 500 is used as a finger guiding region to which a finger of a user operating the sheath 5 contacts.

The back wall of the finger guiding part 51 is formed as a slope descending to the front portion, in a stepped shape. On the slope, protrusions 510 and recesses 511 are repeatedly arranged so as to increase the friction against a user's finger.

Further, the back wall of the distal part 52 includes a protrusive stopper 55 which prevents the user's finger of pushing the sheath 5 from further moving toward the distal side of the sheath 5. Also, the back wall of the distal part 52 includes a hole 520 which is formed when a locking tab 57 (or cannula fixing part) is molded. Note the stopper 55 is arranged at the vicinity of the center portion in the longitudinal direction, or at the position closer to the distal end side of the sheath 5, so that a larger moment is generated to smoothly pivot the sheath 5, when a user pushes the sheath 5 by a finger.

The sheath 5 includes a collar connection mechanism 54 (or attachment part) having a pair of cylindrical pins 540. The pair of pins 540 is to be attached to the ear holes 33 of the ears 31 at the collar 3, so as to rotatably connect the sheath 5 with the collar 3. Here, each pin 540 is chamfered in order to facilitate the above mentioned connection.

A pair of wing walls 53 is arranged at the proximal end side of the finger guiding part 50. Inside the wing wall 53, a slope 530 is provided in the direction toward the proximal end 501. The slope 530 allows the sheath 5 to be easily attached to the collar 3 (that is, by relatively small force). Further, at the front side of the wing wall 53, is arranged a groove 531 (or cannula fixing part) which fits with the sheath fixing protrusion 35 of the collar 3. Here, it should be noted that when each sheath fixing protrusion 35 of the collar 3 turns to fitting with the corresponding groove 531, the pair of wing walls 53 is to be expanded outside just before the fitting.

An opening 58 of the sheath 5 has a locking tab 57. The locking tab 57 is formed by a punching portion of the back wall of the distal part 52 and protrudes inside from the side wall located inside the opening 58. Here, the locking tab 57 is to be bent when the cannula 2 is introduced into the opening 58. This allows the cannula 2 to move past the side of the locking tab 57. Hereby, the locking tab 57 persistently locks the cannula 2 thus moved past the side of the tab 57 by preventing the cannula 2 from moving back. This locking occurs automatically in the above mentioned movement. In other words, this permanent locking of the cannula 2 fixed inside the sheath 5 can be achieved once the cannula 2 has been introduced into the opening 58 thereby to move past the side of the locking tab 57. Herein, the rib 56 positions the cannula 2 in the left-and right direction thereof when the cannula 2 is introduced into the opening 58.

FIG. 6 shows the safety needle assembly 100 thus assembled by the respective components. As described hereinbefore, the safety needle assembly 100 thus assembled may be packaged in a blister packaging or the like in the state of FIG. 6, or may be packaged after the assembly 100 is connected with a syringe (not shown).

Next, referring to FIGS. 6 and 7, a method for using the safety needle assembly 100 will be explained in case a user exposes the cannula 2 from the assembly 100 as shown in FIG. 5.

First, a user pivots the sheath 5 to be apart from the protector 4 so as to remove the protector 4.

After the sheath 5 is pivoted, the user removes the protector 4 and exposes the cannula 2 (see FIG. 7). In this state, the user can use the cannula 2 (for example, to use the cannula 2 for collecting blood from a patient).

Next, referring to FIGS. 7 to 9, a method for using the safety needle assembly 100 will be explained in case a user houses the cannula 2 inside the sheath 5 of the assembly 100 in the state of FIG. 7.

First, after a user has finished the usage of the cannula 2, the user pivots the sheath 5 toward the cannula 2 thereby to have the safety needle assembly 100 be in the state of FIG. 8.

Then, the user pushes the back wall of the finger guiding part 51 by a finger against the sheath 5. This allows the sheath 5 to be further pivoted toward the cannula 2 as shown in FIGS. 9A and 9B. The cannula 2 moves past the side of the locking tab 57 to be engaged with the locking tab 57, and the pair of sheath fixing protrusions 35 of the collar 3 is respectively engaged with the corresponding grooves 531 of the sheath 5. Hereby, the cannula 2 is locked inside the sheath 5. That is, at this timing, the cannula 2 is covered by the sheath 5, and further is locked inside the sheath 5.

As described above, the safety needle assembly 100 in the present embodiment enables the high safety due to the mechanism thereof (that is, securing the lower probability that a user erroneously stings the cannula 2 into a body). Further, this also enables the high operability to be realized due to the structure thereof that the sheath 5 has the stopper 55 at the vicinity of the central portion in the longitudinal direction of the sheath 5, or at the position closer to the distal end side than the central portion of the sheath 5. In other words, the above mentioned positioning of the stopper 55 allows a user to push the sheath 5 by a user's finger at a distal side from the fulcrum (or at the position of the pins 540 of the sheath 5), resulting in generation of a larger moment which enables the sheath 5 to be pivoted by relatively smaller force.

Further, the pair of wing walls 52 each having a slope 530 and a groove 531 in the sheath 5 enables the high operability to be realized. That is, the wing walls 53 projecting from the body of the sheath 5 are easy to be bent outward, and the slopes 530 facilitate the sheath fixing protrusions 35 to be introduced of the collar 3 into the grooves 531. Further, the grooves 531 allow the sheath fixing protrusions 35 to be fixed therein. Those mechanisms enable the sheath fixing protrusions 35 of the collar 3 to be fitted and fixed in the grooves 531 of the wing walls 53 of the sheath 5 with relatively small force when a user pushes the sheath 5 by a user's finger.

Moreover, a user can pivot the sheath 5 by pushing not only the slope provided with a plurality of protrusions 510 and recesses 511 having large friction but also the circular recess 500 to which a user's finger easily fits. Accordingly, this allows the high operability to be realized.

Furthermore, the cannula 2 introduced inside the opening 58 of the sheath 5 is locked by the locking tab 57 besides the grooves 531 of the wing walls 53, allowing it less probable that the cannula 2 is exposed after being housed inside the sheath 5. That is, this makes the safety higher. Further, the locking tab 57 is easily molded, allowing the cannula fixing part to be formed at lower cost.

Further, each ear 31 of the collar 3 has a chamfer inside the ear 31, whereby the sheath is attached to the collar 3 through the chamfer, allowing the attachment to need relatively small force.

Further, it is possible to realize that the pair of sheath fixing protrusions 35 of the collar 3 is formed respectively in a substantially triangle having a groove 37, which is made in a simple structure.

Here, the detailed explanations for the embodiments have been completed, while the embodiments of the present invention are not limited to the examples disclosed hereinbefore.

For example, if there are a plurality of cannulas with different lengths, different sheaths 5 corresponding to the respective lengths may be used in the present invention.

Further, a variety of modifications may be appropriately performed with respect to specific structures without departing from the scope of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

-   1: Hub -   2: Cannula -   3: Collar -   4: Protector -   5: Sheath -   10: Distal End -   11: Proximal End -   12: Through Hole -   13: Rib -   14: Protrusion -   15: Recessed Ring Region -   16, 17: Stage Part -   18: Flange -   20: Blade Surface -   21: Proximal End -   22: Distal End -   31: Ear (or Sheath Attachment Part) -   32: Chamfer -   33: Ear Hole -   34: Distal End -   35: Sheath Fixing Protrusion -   36: Circular Ridge -   37: Groove -   38: Proximal End -   39: Through Hole -   40: Distal End -   41: Proximal End -   42: Rib -   50: Finger Guiding Part -   51: Finger Guiding Part -   52: Distal Part -   53: Wing wall (or Cannula Fixing Part) -   54: Collar Connection Mechanism (or Attachment Part) -   55: Stopper -   56: Rib -   57: Locking Tab (or Cannula Fixing Part) -   58: Opening -   100: Safety Needle Assembly -   301: Protrusion -   302: Ring-shaped Ridge -   500: Circular Recess -   501: Proximal End -   510: Protrusion -   511: Recess -   520: Hole -   521: Distal End -   530: Slope -   531: Groove (or Cannula Fixing Part) -   540: Pin 

1. A safety needle assembly with a sheath, comprising: a hub including a proximal end connecting with a syringe and a distal end; a cannula including a proximal end connecting with the distal end of the hub, a lumen extending in a longitudinal direction of the cannula, and a distal end; a collar attached to the hub and having a sheath attachment part; a protector covering the distal end of the cannula by being attached to the hub or the collar, and being detachable to expose the distal end of the cannula; and an opening partially extending along at least a longitudinal direction of the sheath so as to house the cannula, wherein the sheath further comprising: a cannula fixing part of fixing the cannula housed in the opening; an attachment part rotatably supporting the sheath in a direction of housing the cannula when the protector is detached to expose the distal end of the cannula, the attachment part being attached to the sheath attachment part of the collar; and a protrusive stopper arranged at a vicinity of a central portion of the sheath in a longitudinal direction in which the central portion is located at an opposite side of an aperture of the opening, or arranged at a position closer to the distal end of the sheath than the central portion, so that a finger of a user pushes the stopper of the sheath thereby to house the cannula in the opening.
 2. A safety needle assembly with a sheath, comprising: a hub including a proximal end connecting with a syringe, and a distal end; a cannula including a proximal end connecting with the distal end of the hub, a lumen extending in a longitudinal direction, and a distal end; a collar attached to the hub, including a sheath attachment part and a pair of sheath fixing protrusions; a protector covering the distal end of the cannula by being attached to the hub or the collar, and being detachable to expose the distal end of the cannula; and an opening partially extending along at least a longitudinal direction of the sheath so as to house the cannula, wherein the sheath further comprising: a cannula fixing part comprised of grooves respectively fitting with the pair of sheath fixing protrusions when the cannula is housed in the opening, and a pair of wing walls each of which is provided with a slope arranged inside the wing wall in a direction from the groove to the proximal end of the sheath; and an attachment part rotatably supporting the sheath in a direction of housing the cannula when the protector is detached to expose the distal end of the cannula, the attachment part being attached to the sheath attachment part of the collar.
 3. The safety needle assembly as described in claim 1, wherein the sheath comprises a circular recess used as a finger guiding region to which a finger of a user of operating the sheath contacts, the circular recess being arranged at a position closer to a proximal end side than the stopper located at an opposite side of an aperture of the opening, and a slope having a plurality of protrusions and recesses with large frictional resistance arranged between the circular recess and the stopper.
 4. The safety needle assembly as described in claim 1, wherein the sheath comprises a locking tab as a cannula fixing part which protrudes from a side wall of the opening to an inside of the opening, the locking tab passing the cannula introduced in the opening and then locking the cannula.
 5. The safety needle assembly as described in claim 1, wherein an attachment part of the sheath is comprised of cylindrical pins, and a sheath attachment part of the collar is comprised of protruded ears including a pair of through halls each of which houses the cylindrical pin, and inside chamfers each of which receives the cylindrical pin.
 6. The safety needle assembly as described in claim 2, wherein a pair of sheath fixing protrusions of the collar respectively have a substantially triangle shape and are arranged at an opposite position of the sheath attachment part, the pair of sheath fixing protrusions having grooves respectively fitting with a pair of wing walls of the cannula fixing part.
 7. The safety needle assembly as described in claim 2, wherein an attachment part of the sheath is comprised of cylindrical pins, and a sheath attachment part of the collar is comprised of protruded ears including a pair of through halls each of which houses the cylindrical pin, and inside chamfers each of which receives the cylindrical pin. 